Reversible rotary engine.



No. 642,785. Patented Feb. 6, 1900. .1. cams.

REVERSIBLE ROTARY ENGINE.

(Application filed Jan. 28, 1898.) (No Model.) 2 Sheets-Sheet I.

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Patented Feb. 6, I900. J. CRAIG.

2 Sheets-Sheet 2.

Willi/d REVERSIBLE ROTARY ENGINE.

(Application filed Jan. 26, 1898.)

(No Model.)

A llim WHEN E s SE 5 4M NITED STATES PATENT OFFIGEV JOSEPH CRAIG, OF HIGHLAND SPRINGS, CALIFORNIA.

REVERSIBLE ROTARY ENGINE.

SPECIFICATION forming part of Letters Patent No. 642,785, dated February 6, 1900.

Application filed January 26,1898. Serial No. 668,069. on model.)

To all whom it may concern.-

Be it known that I, JOSEPH CRAIG, a citizen of the United States, residing at Highland Springs, in the county of Lake and State of California, have invented certain new and useful Improvements in Reversible Rotary Engines; and I do hereby declare the following to be a full, clear, and exact description of said invention, such as will enable others skilled in the artto which it most nearly appertains to make, use, and practice the same.

My invention relates to improvements in reversible rotary engines, the object of my invention being to provide such an engine in which the rotary piston-carrier shall act as an automatic steam cut-off, whereby the steam may be used expansively to propel said carrier, and in which the pistons shall have a steam-tight engagement with the cylinder without binding and leakage of the steam will be prevented without undue friction.

My invention therefore resides in the novel construction, combination, and arrangement of parts hereinafter fully specified, and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is a longitudinal vertical section of my improved rotary engine. Fig. 2 is a side View thereof. Fig. 3 is a transverse vertical section. Fig. 4 is a longitudinal section taken on the line at 4 of Fig. 1. Fig. 5 is a longitudinal section through one of the pistons in its position in the chamber, and Fig. 6 is a transverse section of the same.

1 represents the casing of the rotaryengine, which is of cylindrical form mounted on a bed-plate 2 and closed at the ends by the cylinder-heads 3.

The cylinder is provided with ingress-apertures 4 4 and egress-apertures 5 5 for the steam, the egress-apertures being preferably made larger than the ingress-apertures to allow a free excape of the expanded steam at the exhaust. The feed-pipes 6 and exhaustpipes 7 are provided with cocks 8 9, so that the engine can be reversed at will by manipulating the proper cocks. Within the cylinder, in one side thereof, is fixedly mounted the annular segment 10, the middle portion of said segment being cylindrical or annular in curvature, but the terminal portions tapering to an edge, as shown.

The cylinder-heads 3 have each a central hub or boss 11 and are apertured, as at 12, through said hub to receive the shaft 13 of the engine, said aperture being enlarged, as at 14, to receive first the packing 15 around the shaft and then the packing-box 16, the latter being suitably bolted to said cylinderhead.

Upon the shaft 13 is keyed, as at 17, the

cylindrical piston-carrier 18. Said carrier re-- volves snugly within the annular segment 10 and is provided with six steam-chambers 19, arranged to admit steam from one of the feeds pipes 6 to the steam-space 20 between the piston-carrier and the cylindrical casing 1. When a sufficiency of steam has been admitted, the steam-supply is cut off automatically by rotation of the carrier, and the steam then acts by expansion. In the cylindrical face of the piston-carrier 18 there are formed three channels 21 to receive pistons 22. Said channels and pistons extend entirely across the carrier between the cylinder-heads, and the pistons are caused to reciprocate radially in said channels by the pressure (or exhaust) of steam admitted into the channels behind said pistons through the inlet 23 in one of the cylinder-heads. A similar outlet 24 is also provided in the cylinder-head to release the steam from the channel 21 before the piston 8 moves inwardly again. Said openings 23 and 24. are made elongated in form, so that either of them can be used as an inlet and the other as an outlet. Each of the openings 23 24:is connected by pipes 25 with the feed and exhaust pipes 6 7 on its own side of the engine, so that steam is supplied simultaneously to either of the apertures 23 24: simultaneously with the admission of steam to the ingressaperture 4. on the side of the engine corresponding to said aperture and exhausted from the other of the said apertures 23 24 simultaneously with the exhaust from corresponding exhaust-aperture 5.

The inlet 23 to admit the steam behind the piston to force the same radially outward is so arranged relatively to the ingress-aperture at that said radial movement is made with suiiicient rapidity to maintain a steamtight bearing of the outer edge of said piston against the inner surface of the casing. In like manner the outlet 24 is arranged to exhaust the steam from behind the piston when said piston arrives at the edge of the inclined portion of the segment 10.

In order to provide steam-tight bearings of the ends of the pistons against the inner surfaces of the cylinder-heads, the piston is made in two sections 26 27, of which one section 26 is provided with a tongue 28 and the other section with a groove 29, in which said tongue on the other section slides. The section 27 has also a dowel-pin 30, sliding in a correspondingly-shaped recess 31 in the other section 26. The groove 29 is made deeper on the side of the piston which is next the shaft than on the farther side, so that the tongue 28 does not reach the bottom of the groove. Thus there is left a steam-space between the two sections, and the pressure of the steam in said space tends to spread the two sections apart and hold them steam-tight against the inner surface of the cylinder heads. Inasmuch, however, as the pistons do not extend radially the whole distance from the shaft of the carrier to the inner wall of the casing there would be a leakage of steam from the steam-space 20 between the ends of the carrier and the inner Walls of the cylinder-heads. This is provided against by means of six steel packing-blocks 32, one at each end of each piston. Said packing-blocks are let into recesses 33, formed in the carrier adjoining the ends of the channels 21, and between the inner edge of each block and the opposing face of its recess is provided an elliptical spring 34, the oflice of said spring being to force the block outward and make a steam-tight bearing of the outer edge of said block against the inner wall of the cylinder-head. The steam entering the space occupied by the spring serves the same purpose. The recesses 33 extend to the shaft of the carrier, and the blocks 32 are thus placed so that their inner edges are in close proximity to said shaft. Thus escape of the steam from the space 20 is effectually prevented.

By the regulation of the ingress and egress of steam to the piston-blocks a perfect steam cushion is provided and the pistons always work smooth without jar or rattle.

In case it is not required that the engine should be reversible one of the ingress-ports, one of the egress-ports, and three of the steamchambers 19 may be dispensed with.

I claim 1. In a rotary engine, the combination, with a casing, and a rotary piston-carrier having channels, of sectional pistons carried therein, the sections of said pistons being extensible endwise from each other, means for intermittently admitting steam between said sec tions to extend the same, and means for guiding said sections in alinement with each other while preventing passage of the steam entirely between said sections to the outer edge of the piston, substantially as described.

2. In a rotary engine, the combination with a casing, and a rotary'piston-carrier having channels, of sectional pistons reciprocable therein, means for admitting steam between said sections to spread the same, packingbloeks adjacent to the ends of said pistons, and means for admitting steam behind said blocks to press the same endwise against the casing, substantially as described.

In witness whereof I have hereuntosigned my name, in the presence of two witnesses, this 15th day of January, 1898.

JOSEPH CRAIG.

lVitnesses:

R. F. KERR, FRANK BUCKNER. 

